


the lighthouse or the storm

by callunavulgari



Category: Stranger Things (TV 2016)
Genre: Alternate Universe - Canon Divergence, Alternate Universe - Merpeople, Getting Together, M/M, Mild Sexual Content, Pre-Season/Series 03
Language: English
Status: Completed
Published: 2020-08-15
Updated: 2020-08-15
Packaged: 2021-03-06 04:14:09
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 7,637
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25907161
Author URL: https://archiveofourown.org/users/callunavulgari/pseuds/callunavulgari
Summary: “Billy?” Steve asks, head tilting in confusion. His voice sounds strange, bleary, like he’s still waking up.Billy’s mouth is full of sharp teeth that aren't well-suited to making words, so he keeps his mouth shut, fighting off the change with every breath as he stares Steve down, willing him to fuck off. Steve doesn’t move, swaying on his feet a little as he takes first one, then two steps closer to the edge of the water.“What are you doing here?” Steve murmurs, his next step bringing his toes into contact with the water. He flinches, glancing down to his feet as if shocked by the unexpected coldness. He blinks several times in quick succession, shaking his head to clear it. He looks at Billy again. “The water’s freezing.”Billy grits his teeth, then says, as carefully as he can with his mouth full of razors, “Fuck off, Harrington.”
Relationships: Billy Hargrove/Steve Harrington
Comments: 9
Kudos: 253





	the lighthouse or the storm

**Author's Note:**

> This was supposed to be for MerMay. I wrote about 3k of it and realized it wasn't going to get finished in time. Takes place before season 3, obviously. I'm gonna view it as canon divergence and you can too.

Billy’s mom’s tribe had come up from tropical waters. Over the course of many years they had slowly migrated across the Pacific until they ended up in the warm, shallow waters alongside the coast of sunny California. And there they had stayed, or at least stayed long enough for Billy’s mom to meet Billy’s dad.

They weren’t like their cold-blooded cousins who preferred the frigid depths of deep sea trenches, built instead for the warmer waters of the island reefs. Billy had only ever seen his mom, but she told him that they came in all sorts of jewel-bright colors. Searing reds and sunset oranges, blues and yellows the color of poisonous frogs. They came with frills and iridescent scales, spots and stripes. And while they were softer bodied than their northern cousins, what they lacked in sharpness they made up for in venom. 

Billy’s mom had told him when he was little to never ignore his instincts. At five years old he was already old enough to hear the call. Old enough to make the change. It was important, she’d told him, not to ignore it. When the sea called for him, it was his job to give it what it wanted. 

His kind weren’t meant to be so far from the ocean, but it’s not like his dad had asked for his opinion when he moved them to a land-locked state in the middle of nowhere.

Those first few months in Hawkins, he’d taken a lot of baths. Ate his weight in fish that tasted of freezer burn and salty fries. He passed the time thinking of anything other than the ocean, steeping himself in rage and resentment. He went out and partied with the locals, drinking himself stupid whichever day of the week he wanted and staggering through the days at school with a pounding headache the next day, his thighs so dry they itched.

When he slept, Billy heard the call in his sleep - phantom whalesong and a voice like his mother’s in his ear, whispering for him to come back. To go to them. To just dive, dive deep. 

When he was awake, the call was worse. 

The itching got so bad in December that the skin along his calves and thighs began to flake, huge swathes of skin peeling off in translucent clumps, leaving what was left behind raw and irritated. The headaches got worse. His gums began to ache, pinpricks of sharp pain where his second set of teeth threatened to shear through.

He stopped sleeping. Started stockpiling fish from the grocery store and eating it raw in his bedroom after dinner, his blunt, human teeth crunching through tiny bones. On the bad days, he would wait for his dad to leave and skip school just to sit in the bathtub, his teeth grit hard to keep himself from shifting in the too small tub.

And then, six months and some change into living in Hawkins, he gets desperate enough to drive down to the quarry.

The night he chooses is a good one. It’s early March and the sky is clear - stars bright, the moon a sliver of light high above him. It’s still cold. March in the midwest is worse than any winter back home, but he can hear whale song as he drives, the sound of it deafening in his ears. He turns up the music in his car, makes it something loud and angry to try to drown it out.

The thing is - fresh water is a horrible fucking substitute for salt water. You drop a fish from the ocean into a lake and it’s going to have some problems. But Billy isn’t a fucking fish, and he's desperate enough to take the gamble, so he’s hoping for the best.

The water, when Billy gets there, is frankly disappointing. It’s murky, dark with mud and silt, and smells stagnant. 

He doesn’t know what the fuck he was expecting. A miracle? For a shitty man-made lake to magically transform into something resembling an ocean? No. This is what he has to work with, so he might as well make the best of it. 

He quietly removes his clothing, eyeing the water warily for any signs of movement. It feels wrong. No waves slap against the shore, the surface of the black water calm and still, like a mirror. When he takes his first step forward into the water, his feet try to slide out from under him, the smoothed over rocks on the shore thick with slime. 

Billy wades up to his waist, mud squelching between his toes. The water is colder than what he’s used to. He’s breathing faster now, eager for it, his gum line prickling with anticipation. He swallows once, hard, when the water reaches his chest. 

Just as he’s readying himself to submerge, there’s a noise from the forest behind him.

Billy pauses, half-changed already, teeth pricking up through his gums, the places between his fingers going webbed. And then, against his better judgement, he turns to look just in time to see Steve Harrington stagger out of the forest, looking vaguely wild-eyed. 

It’s been months since Billy last saw Steve, spotting him only in passing after the winter break. Billy’s tried to avoid him since that night at the Byers, ignoring him at basketball practice and steering clear of him at parties. Steve was bad news for more reasons than one, and til now, Billy had done a damn good job of pretending that he didn’t exist.

Steve Harrington is dressed in what look like pajama bottoms, a threadbare t-shirt the only thing that protects him from grasping, thorny branches. Billy watches Steve’s thin chest heave for breath, too close to the change to not smell the blood beading along the dozens of scratches up and down his body. It makes Billy's teeth itch. Makes him hungry.

Steve turns and his frantic gaze lands on Billy. He blinks, and then freezes, his entire body going stiff. Absurdly, Billy realizes that Steve seems to be barefoot, his feet dark with mud up to the ankles.

“Billy?” Steve asks, head tilting in confusion. His voice sounds strange, bleary, like he’s still waking up. 

Billy’s mouth is full of sharp teeth that aren't well-suited to making words, so he keeps his mouth shut, fighting off the change with every breath as he stares Steve down, willing him to fuck off. Steve doesn’t move, swaying on his feet a little as he takes first one, then two steps closer to the edge of the water. 

“What are you doing here?” Steve murmurs, his next step bringing his toes into contact with the water. He flinches, glancing down to his feet as if shocked by the unexpected coldness. He blinks several times in quick succession, shaking his head to clear it. 

He looks at Billy again. “The water’s freezing.”

Billy grits his teeth, then says, as carefully as he can with his mouth full of razors, “Fuck off, Harrington.”

Steve has the nerve to look affronted, his nose crinkling up in displeasure. “You’re going to give yourself pneumonia.”

“I don’t care,” Billy bites out in choppy syllables.

Steve’s jaw tightens and his eyes narrow. He goes rigid, his fists clenching at his sides. He looks, god fucking save him, _determined_.

“Well,” he says, sharply. “I fucking do. I’m not going to let you catch your death out here.”

Billy laughs, the sound coming out a touch hysterical. Under the water, his feet are mostly still feet-shaped, planted firmly on the ground. But he can feel the webbing between his toes and the scratch of scales against his thighs. He’s had to hold off a change before, but never like this, never tits fucking deep in water after two months of nothing. He can hear the song, his very nature fighting him to surrender. 

_Just dive_ , a voice whispers. _Dive deep. Come home._

Billy shudders, letting his eyes slip closed. He takes a step backwards, away from Steve, and has precious seconds to realize he’s run out of ground when he hears a shout and then, he’s under.

There’s no fighting it. The water closes in over his head and Billy’s gills, already half-formed, flare wide. The rest of the change is damn near instantaneous. His teeth slip the rest of the way free of his gums. His bones crack, two legs shifting into a single, powerful tail. The spines come last, running up the length of his spine and down his forearms, from elbow to wrist. His secondary eyelids settle over his eyes and Billy blinks rapidly to clear his vision, shaking his head to clear the disorientation. Under the surface of the water, the lake is cool and dark, the murky water more green than black, thick with silt and debris. It tastes just as horrible as it looks, brackish and thick with grime. He gags on it, doubled over and choking, his gills flaring wider as he panics. 

Arms wrap around his waist and Billy thrashes, his tail slapping against the bank and muddying the waters even further. He gasps silently in the dark, fighting Steve’s hold on him until the arms that had been clamped around his armpits finally let go. 

He’s still not breathing right- and he thinks again of the saltwater fish dropped into a fucking lake. It wouldn’t die immediately, Billy thinks. It would just take on too much water until it died. Until it fucking _exploded_. It will be fine, he thinks wildly. This can be controlled. He’ll adjust to the water. He just needs to get used to it and then it will be fine.

Billy catches a flash of movement out of the corner of his eye and then Steve is sliding another arm around his rib-cage, pulling Billy slowly and inexorably to the surface. He tries to slip loose, fighting the hold, but Steve has a better grip this time, Billy pulled flush to him, chest to chest. 

If Billy fights him on this too much, he could hurt them both.

He wills himself calm, squeezing his eyes shut and reeling back the change just enough to rid himself of the obvious things - the gills in his neck, the teeth, the flared fins along his hairline, and the spines that could kill Steve in under a fucking minute if he so much as pricked himself. Billy breaks the surface of the water with a gasp and feels Steve do the same. Steve is still too close, his arm clutching Billy to him like he’s afraid he’ll wiggle off again. His chest is heaving against Billy's and his breath is hot against the curve of his cheek.

After a moment of treading water, Steve starts tugging them towards the shore. 

Billy balks.

“Stop _fighting_ me,” Steve gasps. 

“Stop _making_ me fight you,” Billy gasps back, pushing at Steve’s arm until he finally, _finally_ , lets go.

Billy pushes back and away so quickly that the dizziness flares back into existence and for a moment, he doesn’t know which way is up. He’s under the water again and can’t breathe for the first time in his entire fucking life because his body isn’t adapted for fucking lake water. He sputters back to the surface, panting, hair in his eyes. The dizziness passes. 

He and Steve stare at each other. 

“You gonna tell me why you’re trying to drown yourself?” Steve asks him, his tone acidic.

“You gonna tell me how it’s any of your business?” Billy bites back and hisses, jolting backwards when Steve tries to make another grab at him. “What the fuck are you doing out here, anyway?”

Steve glares at him. “I sleepwalk. Sometimes.”

Billy scoffs. 

“Into the woods?” he asks, his voice incredulous. 

Steve’s cheeks flush. “My house isn’t that far from here.”

“Dangerous place to be sleep-walking though,” Billy muses, his gaze shifting to the cliffs on the other side of the quarry. He’d hate to think about what would happen if Steve walked off one of those ledges. At least if he’d walked into the water like this, the shock of it might wake him up. If he walked his way right off a cliff... he'd never get the chance to wake up to realize just how badly he'd fucked up.

“Tell me about it,” Steve sighs. “It’s not like I plan on doing it. It just happens.”

They lapse into silence, staring at each other warily, the churn of the water around them made all the louder for it. Billy is acutely aware of how inhuman he is beneath the surface, his tail fins dragging against the muck at the bottom of the lake. He needs to change back, but there’s an ache that’s settled deep into his bones that just won’t fucking let him. 

He _needs_ this. 

“Are you going to get out?” Steve asks him, but he’s got this put upon expression on his face like he already knows the answer. 

“Wasn’t planning on it,” Billy tells him, smoothing his hair back from his forehead. 

Steve stares at him for a minute longer, then sighs, pushing away from Billy and back towards shallower water. Billy watches him go, feeling a strange combination of relief and regret well up inside of him.

Once Steve has reached a place where he can reach the bottom though, he stops and fixes both arms over his chest, turning a glare on Billy.

“All right,” he says, settling back on his heels easily. “I’ll wait.”

Billy barks out a disbelieving laugh. “Wait for _what,_ Harrington?”

Steve shrugs. “Look, I’m not gonna just leave your ass here to slip on some rock and drown. I don't need that shit on my conscience. So, I’m staying.”

“You’re _serious_?” Billy asks. 

Steve flashes him a shitty little grin, all teeth. “As a heart attack.”

“I don’t need a fucking lifeguard,” Billy snaps. “I grew up on the coast.”

“Then I’m sure you won’t mind a spectator.”

Billy eyes him, seething. He’s so angry that his teeth are prickling at his gums again. 

“For god’s sake, Harrington, you’ve still got your clothes on,” he snaps. “Just get out!”

Steve’s eyebrows hit his hairline. “So, you’re saying you want me to take off my clothes.”

Billy snarls. “That’s not what I-”

“Oh no,” Steve says, nodding sagely. “I understood perfectly.”

As Billy watches, horrified, Steve begins to squirm out of his t-shirt. The soaked fabric clings to him and he has to fight to get it over his head, but once it’s off, he flings it in Billy’s direction, where it lands in the water with a loud plop.

Billy stares at it as it starts to sink, then turns to look at Steve. “I’m not fishing that out for you.”

Steve shrugs. “That’s okay. It was old.”

A moment later, Steve’s pajama bottoms hit the beach a few feet from Billy’s clothes. Billy closes his eyes. He takes a deep, calming breath through his nose and very carefully, lets himself sink below the water.

Billy doesn’t let himself stay under for too long, because he doesn’t actually want Steve to get his panties in a twist and come charging to his rescue. He stays under _just_ long enough, watching the eerie green water change around him. His tail startles a nearby catfish, which goes darting off into the gloom. It makes Billy want to laugh. If he were alone, he would chase that fish until he caught it, snap it up between his jaws and feast. With Steve here, he just watches it go. 

After another moment of quiet, he lets himself surface, blinking the water from his eyes. He’s not altogether unsurprised to find Steve sheepishly treading water a couple feet away, much closer than he was before Billy went under.

Billy grins at him, wide and sharp, and makes his tone as scathing as possible when he asks, “Planning on saving me, again?”

Steve flushes, his hair plastered to his forehead and cheeks. As Billy watches, he scrubs it back with one hand. 

Feeling daring, Billy closes the distance between them, until they’re face to face again, and he can see up close the way that Steve’s expression twists when he’s angry. It’s been months since Billy was this close to Steve. Months and months of stolen glances in hallways and locker rooms. It’s intoxicating to have him this close again. Billy had somehow forgotten over that horrible winter just how much Steve got under his skin.

“Oh no,” Billy deadpans, smirking as he swims slow circles around Steve. “Save me, Steve. I’m drowning.”

Steve huffs, but it looks like he’s trying to fight a smile. “You’re a real asshole, you know that?”

Billy hums, amused. Why deny it? It’s true.

Steve makes another little huffy sound and Billy rolls his eyes. “You really don’t have to be here.”

“I do,” Steve tells him, and Billy turns to face him, surprised by the steel in his voice. He drifts closer, and then, in a fit of daring, drapes himself across Steve’s shoulders, angled sharply to keep his tail out of reach.

“Why?” Billy asks him, simply.

Steve shivers, and Billy thinks hard about biting him, right where his neck meets shoulder. He’s willing to bet that Steve would melt. 

“Because,” Steve says, and Billy presses closer. Makes his voice soft. Intimate. Coaxing.

“Because _why_?”

He says it directly into Steve’s ear and is pleasantly surprised at the full body quiver that goes through him. Steve swallows. 

“People die," he says at last. "In the water."

Billy hums a quiet agreement. He knows. Billy had seen the aftermath more than once of what happened to humans who thought they knew the water. Who forgot that it was a dangerous thing no matter how well you thought you knew it. 

Steve takes a deep breath and then says, "Before you came to Hawkins, a girl _died_ in my pool.” 

Billy pauses, taken aback. He _hadn’t_ known that. He'd heard about Wheeler's little friend going missing, but nobody told him that she _died_. That was the kind of thing that the rumor mill seized onto and never let go. But he guesses that Steve’s parents _are_ rich enough to obscure the truth a bit. Nobody had to know that she went missing from Harrington’s house. They definitely didn't have to know she'd died.

“I wasn’t there,” Steve is saying, his face set. “She died alone and fucking _scared_ , and I don't care how well you think you know the water, I'm not leaving you alone out here.” 

Billy pulls away from Steve slowly and looks him straight in the face. “I’m not that girl, Steve.”

“I know.” Steve shrugs. “I’m still staying.”

Carefully, Billy touches Steve’s bottom lip, where it’s beginning to go blue. Steve’s eyes are wide and dark. Billy wants to eat him alive. “You’re cold.”

“Not _that_ cold,” Steve protests, despite the fact that his entire argument up til this point had been pneumonia. 

Billy sighs, the fight going out of him. The call is quieter now, as satisfied as it’s going to get tonight. There’s a part of him that regrets - that wants to explore the depths of this lake, as wrong as the water is. 

He’ll come back later.

He shifts quickly and quietly, making a little noise in the back of his throat when his bones snap apart. It takes the span of a breath. Maybe two. But that small noise is the only indication that anything has even happened. And then he’s shoving Steve back towards the shallows. 

“All right,” Billy says. “Come on, Harrington. Let’s get you home.”

* * *

Billy keeps coming back to the quarry as spring ripens. Most nights, he’s alone and can explore the lake to his liking - chasing fish and snapping at their tails. Other nights though, Steve is there, casually sprawled on a log near the shore, and Billy will look at him, one eyebrow raised before stripping down and wading in.

As the nights get warmer, Steve joins him in the water more often. 

Then one night, as he’s floating on his back, he says, “I have a pool, y’know.”

Billy, who hasn’t forgotten the conversation they’d had that first night, says, “Yes, I know.”

Steve tips his head to look at him, his face streaked with water. 

“I’m just saying,” he says. “It’s gotta be safer than this.”

Billy thinks of the dead girl and privately thinks that she probably would have disagreed. But she was a human and Billy is decidedly not. 

“You offering to throw a pool party, Harrington?”

It’s not a no and Steve knows it because he smiles, small and pleased. “Just for you.”

Billy knows it won't be the same. For one, he won’t be able to change. The lake at night is black and murky, dark enough to obscure Billy’s tail. A pool, even in the middle of the night, would be lit up. The water would be clear. But he thinks it would probably be worth it, every once in a while.

“Yeah,” he says. “All right.”

* * *

Steve makes it happen the very next Saturday. His parents are out of town, so he suggests they make a day of it. Beer, pizza, warm sunshine and cool water. 

Billy makes sure to show up early, a twelve pack of shitty beer in one hand and a shit-eating grin on his face. There’s something in his chest besides sea song, excitement thrumming within the cage of his ribs, and when Steve answers the door, squinting blearily against the blinding glare of the sun, Billy knocks their shoulders together as he pushes past him, carelessly tossing the beer into his arms. He slides his sunglasses down his nose, whistling softly as he takes it all in. Steve’s muttering quiet expletives behind him as he kicks the door shut, the heat that had been wafting in through the open door vanishing, replaced with the frigid chill of the AC. Billy fights down a shiver.

“Fuck,” Steve tells him, padding past Billy and setting the beer on a gleaming table of what looks like solid fucking oak. “I didn’t mean for you to come over before noon.”

Billy shrugs, unconcerned. He’s still looking around in disgusted awe. Just from where he’s standing, he can spot at least six pieces of furniture more expensive than his car. A china hutch peeks out from around the corner to the next room, fancy porcelain cups with intricate little designs and gold fucking rims. 

“Should have said that then,” Billy mutters, stepping around Steve and into what must be the kitchen. Billy had thought that it being a kitchen, it couldn’t be more upsetting than the foyer, but turns out he was fucking wrong. There’s all sorts of bullshit fancy kitchen gadgets tucked into their own little alcoves on the polished marble kitchen counters. The tile under his feet is gleaming and perfect, so shiny that Billy can see his face in it.

“Fuck, Steve,” he says, making a face when he spots the espresso machine. He’d be willing to bet good money on the fact that it actually came from Italy. “You didn’t tell me that you were _this_ fucking loaded.”

Steve shrugs, looking a little uncomfortable. 

“It never came up,” he says, pushing up his worn t-shirt an inch so he can scratch a spot low on his belly. Billy tries not to stare. “Most people already know, so I didn’t think about.”

Billy snorts. “There’s knowing and then there’s _knowing_.”

“Yeah, well,” Steve says, stifling a yawn behind his hand. He looks bored and a little embarrassed, his cheeks pink. “While _you’re_ getting your fill here, _I’m_ going to go change into some shorts.”

Billy waves him off, poking through the weird appliances. He doesn't even know what half of these _are_. Who the fuck needs all this shit?

“Don’t steal anything,” Steve calls as he’s jogging up the stairs, and Billy turns just in time to see him tugging his shirt up over his head. Billy takes a moment to look, because he is weak and _mostly_ human, his gaze drifting from sharp freckled shoulders to the base of Steve's spine. There are two little dimples there. Billy wants to fucking bite them.

“Get it together,” he hisses to himself, slapping his wallet and keys down onto the counter. His fingers leave a smear of dirt behind on the white of the counter and for a moment he stares at it, absurdly proud of himself for that small indication that he - little more than gutter-trash, left a mark on this place. He sneers, turning away, and tears off his tank top as he goes. He carefully doesn't pay attention to how it looks settled on the Harrington’s perfectly polished floor, and finds the back door, flinging it open wide.

The pool is big enough to swim in. Thank fucking god.

He kicks off first one shoe, then the other, practically tripping over himself in his eagerness to get out the door. He takes a step out onto the grass, relishing in the feel of it curling between his toes, and lets out a quiet little sigh of relief. He's crossed the yard before he knows what's happening and for a moment, he just stands there, feet from the diving board, the concrete slowly scorching the soles of his feet. The water beneath him is cool and blue, welcoming. But when he inhales, the illusion is broken. Instead of the warm comforting scents of home - salt and brine thick on the air, this place reeks of chemicals. The water is still, placid. It doesn't push and pull with the tide.

It’s no ocean. But like any body of water, it calls to Billy anyway. 

So he swallows, remembering at the last minute to hold back the change, and steps into the pool. 

Lets himself sink. 

Fucking bliss.

* * *

When Steve emerges some twenty minutes later, he’s got aviators perched on the bridge of his nose and is sporting the most hideous swim trunks that Billy’s ever seen in his life, an eye-searing neon pink and teal. He’s procured a red float from somewhere, which he tosses in Billy’s direction. The pack of beer is tucked up against his side, one arm carefully wrapped around it.

As Billy watches, Steve staggers over to a lounger and sets the pack of beer to the side, then drags the lounger loudly across the concrete, until it’s right up against the edge of the pool. And then he collapses into it, the force of his full weight being thrown onto it making the rubbery material sag dangerously. Then he gropes around with one hand until he finds the beer and unceremoniously pops the tab.

He pauses, looking at Billy.

“You really like the water,” Steve murmurs, cocking his head.

Billy, who is floating spread-eagled on his back, shrugs. 

“What can I say,” he says. “I was born a fish.”

And then he snickers.

Steve doesn’t get the joke, but makes a noise of amusement anyway. 

Billy sighs and kicks himself closer to Steve, reaching for the red float as he goes. Once he’s reached the other side of the pool, he heaves himself up onto it. It’s a decent float. Just enough give that he can still feel the water against his skin. He makes an impatient gesture in Steve’s direction.

“Gimme a beer before they get warm,” he demands, hand outstretched. Steve snorts at him, picks up a can, and unceremoniously chucks it at him.

That’s how they spend the next few hours - Steve stretched out on his lounger getting progressively redder as Billy sprawls across his float, sipping beer after beer. At some point around one, Steve vanishes back into the house and when he comes out, he’s cradling a bag of chips. There’s fresh sunscreen smeared into his skin, the white goop still visible across the bridge of his nose. Billy can smell it as he gets closer, the thick, coconut-y scent of it that takes him back to familiar sun-warmed beaches and noisy boardwalks. 

Billy watches Steve settle back onto the lounger, his trunks riding up his thighs as he pushes himself back. Steve rummages in the bag of chips, coming back with a huge handful, which he proceeds to try to cram into his mouth all at once. Crumbs spill across his chest.

Billy licks his lips and makes a quick decision, pushing off of the float. 

It’s been a while since he was fully submerged, so the water closing around his sun warmed chest is shockingly cold. He shudders a little, gooseflesh spreading up and down his arms, and wades his way over to the side of the pool. 

Steve blinks down at him. “Yes?”

Billy props himself up against the edge, the grit of the concrete digging its way into his elbows, and pushes himself up on his forearms, so he’s half in, half out of the pool. 

He opens his mouth expectantly.

After a handful of seconds, Steve laughs. “Dude, I am not feeding you chips.”

Billy narrows his eyes at him. “How about if I ask _really_ nicely?”

Steve grins at him widely and holds the chips up out of his reach. There’s a piece of chip stuck between two of his teeth. 

“You’re gonna have to jump for it, man,” he says, his voice right on the edge of flirty and teasing, and Billy? Billy has never exactly been the best at showing his attraction to someone, being the type of boy who was more likely to stomp all over your sandcastle than find you a pretty shell. 

So he seizes the foot Steve’s got dangling over the edge of the pool and _yanks_.

When Steve surfaces, he’s spluttering, wet hair hanging in his face. He’s lost his sunglasses somewhere and is blinking up at Billy through wet lashes, his big brown eyes wide and startled. 

“Fucking Christ, Billy,” Steve gasps, and promptly throws himself at him.

Billy laughs, skillfully evading an attempted dunking. He moves slowly away, ducking another swipe of Steve’s arm, and waits a minute to let Steve think he’s got the advantage before he ducks into Steve’s guard, clamping his hands down on both of his forearms and bringing them to his sides.

It’s easy to hold Steve still, because the moment Billy’s got a hold of him, he freezes. 

Billy’s close enough that he can smell Steve over the reek of chlorine - banana boat sunscreen and the salty sweetness of the chips. His chest is heaving, his flesh dotted all over with goosebumps. He blinks slowly, syrupy sweet and Billy gets a glimpse of the thready thrum of Steve’s pulse point, hammering away. 

“You cheated,” Steve tells him breathlessly.

Billy gives him a smile, wide and full of teeth, and doesn’t make a move to release him. “It’s not cheating if I’m just better than you.”

Steve makes a quiet noise of protest, but it’s half-hearted at best. He’s too busy staring at Billy, his pretty eyes glued to Billy’s lips. And well. Billy’s never let someone as pretty as Steve look at him like that without doing something about it. 

When Billy leans in to kiss him, Steve lets out another quiet noise - half shock, half pleasure. Their lips meet.

Billy makes the kiss slow, achingly tender, his hand going up to cradle the back of Steve’s neck, drawing him in even closer. It’s a sweet kiss - one that’s made for testing the waters. And then Steve opens up to him with a sigh, leaning into him, his arms coming up around Billy's sun-warmed shoulders.

The inside of Steve’s mouth is slick and hot and perfect. Billy spends a few long minutes sucking on his tongue before he pulls back, dotting little kisses over Steve’s jawline as he goes. He tastes like barbecue potato chips.

Billy doesn’t pull back far, keeping them in close enough proximity that they're trading breaths, chests heaving. Billy swallows when he gets a good look at Steve’s eyes, gone heated and dark. 

“Good?” he murmurs into the quiet between them, letting his fingers linger over the swell of Steve’s cheekbones, stroking there with the pad of his thumb. Steve shivers, closing his eyes against the touch.

“Good,” Steve whispers back, giving him a jerky nod. Billy watches Steve’s throat work as he swallows and feels the itch of sharp teeth pressing up against his gumline.

When Steve opens his eyes again, there’s a hint of that boy that Billy had seen back at the Byers house, that hint of the playboy asshole that everyone in this damn town _loved_ to talk about. 

Steve smirks, and he's the one who closes the space between them again, catching Billy’s mouth with his own and pressing backwards until Billy’s back thumps up against the side of the pool. Billy lets out a quiet, delighted noise and _squirms_.

This kiss is everything the first promised to grow into, hot and wet, Steve pressed against him with almost bruising force. At some point, Billy tips his head back, and Steve doesn’t waste a beat, leaning down to suck a bruise into his clavicle. 

“Do you-” Steve murmurs breathlessly between kisses, his hands already groping between them, trying to find the ties of Billy’s trunks.

“Yes,” Billy hisses, hips jerking forward when Steve brushes his knuckles over the head of his cock. 

It’s fast and easy, Steve gasping against the side of Billy’s neck as he jerks them off together, the water lapping gently around them. 

When Billy comes it’s with a low groan, dragged out of him like a punch. 

Steve hisses something against his throat, something that sounds a lot like _yes_ and _fuck_ and _Billy_ , his fist working faster between them. Billy leans in to suck on his throat, and that’s it, Steve is gone.

They stay like that for a long moment, eyes closed, breath hot between them. 

Billy opens his eyes to Steve’s eyes already on him. He licks his lips and this time, he gets to see up close and personal how Steve’s eye dip down towards them. He offers Steve a smile.

“If you buy me pizza, I’ll blow you later,” he tells him.

* * *

Billy keeps coming back. At first, he only comes when Steve’s invited him, and they tend to spend an hour or two treading water before they inevitably end up fucking somewhere - be it rushed handjobs in the pool or thorough blowjobs somewhere between the pool and Steve’s bedroom. Once, he jerks Steve off slowly in the pool while Steve’s parents are a couple hundred feet away, blissfully unaware of what’s going on in their own backyard.

As the weeks pass, he starts coming more and more. 

The quarry is still the only place he can really shift, but Steve’s backyard begins to feel increasingly like home. It still isn’t the ocean, but it settles him anyway.

The first month of summer, Billy shifts in Steve’s pool.

It’s three in the morning and Steve is passed out across his bed upstairs. There’s no one around for miles and if Billy doesn’t do something, he’s going to spend the rest of the night restless, the shift calling to him. 

So Billy crawls carefully out from under Steve’s arm and pads downstairs on bare feet. He doesn’t bother with clothes, making his way through the dark kitchen from muscle memory alone and stepping out the back door.

It’s late enough that the air is chilly with oncoming dawn, the grass already wet with dew. Billy steps out onto it, then further, until grass becomes concrete. He steps out onto the diving board, staring at the water. He hadn’t turned on the pool lights when he came out, so the water below him is dark, almost black in the dim light of the moon. 

He takes a dip breath and lets himself slip into the water without a sound. The change is slower this time. He feels each crack of bone, feels the slick as his fins slide free of his spine, and grimaces with discomfort, willing it to come faster, to be like it usually is - instantaneous and pain-free.

When it’s done, he shudders, unfurling himself fully along the bottom of the pool. The chlorine burns his gills, the sting of it just as uncomfortable as the change, and just as he realizes this may have been a bad idea, the lights of the pool flicks on around him.

Billy thrashes, righting himself and forcing the change as quick as he can make it, reeling it back even as he bolts for the surface. 

When Billy hits air, he takes a sharp gasp, blinking repeatedly to clear his eyes.

Steve is there, staring at him. He’s got a hard grip around that monster bat of his and is holding it like he means to swing. Billy stares back, mouth dry.

“I thought-” Steve says, the bat slowly lowering. “I saw you go in.”

“Sorry,” Billy says, his voice hoarse. “I was restless. Wanted to go for a swim.”

Steve is still staring, but after a moment, his gaze shifts away, going to the water around him, like he’s searching for something. Billy's heart thumps faster.

“I thought,” Steve says again, swallowing. “I thought I saw a monster.”

Billy flinches.

Steve catches the movement and his brows scrunch together, confused. He studies Billy and Billy- he feels that at that very moment, Steve can see right through him. He knows that Steve is smarter than he appears at first glance, that there’s more to him than just a pretty face. But who would catch a glimpse of Billy shifted in the pool - just a _glimpse_ \- and jump to _mermaids_?

“It was you,” Steve whispers, eyes narrowing. “It had to have been you. There’s no one else out here.”

“Steve-” Billy tries to say. His teeth itch, every part of his body on edge. 

Steve raises the bat again. He grits his jaw and plants his fucking feet.

“Show me,” he demands, his voice like ice.

Billy could call his bluff. He could laugh Steve off, make him doubt. Tell the whole town that Steve Harrington is fucking crazy. It would probably be the smart thing to do. He’s kept this secret for eighteen years. Eighteen years of no one knowing his secret except for him and the mother who left him for the thing that called to them both. The first time he'd shifted, she'd wrapped him up tight in her arms and told him not to tell his father. That he wouldn’t understand. Billy supposes that probably should have been his first clue - that his mother didn’t even trust the man she called her husband with the truest part of herself.

Eighteen years is a long time to keep a secret. 

But Billy knows, looking into Steve’s dark eyes, that if he were to laugh him off here and now, Billy would lose Steve entirely. This thing between them is new. It’s still just on the cusp of more and this thing, regardless of what Billy decides, could break them.

He swallows. 

“You might not like it,” he says at last, voice cracking.

Steve doesn’t say anything, just keeps staring him down. 

“It could scare you,” Billy feels compelled to warn him.

Steve scoffs. “I’ve met scarier monsters than you, Hargrove.”

That rings true. Billy will have to ask him about it sometime.

“All right,” he says, sagging up to his chin into the water. He sighs, flexing his wrists nervously. “Just… don’t scream or anything.”

 _Or hit me with a fucking bat_ , he thinks, and before Steve can say anything, slips under the water. He doesn’t have to in order to trigger the change, but he really doesn’t want to see Steve’s eyes right now.

The change comes quicker this time, though whether that’s due to his heightened sense of emotion or because his body has adjusted to the water is anyone’s guess. It’s quick, mostly painless, legs fusing together seamlessly, fins releasing a thin film of red into the water around him as they break the skin.

He blinks and his second set of eyelids drops, covering his eyes with a thin protective membrane.

For a while, Billy just sits there, sucking stinging chlorinated water in through his gills. 

But eventually, he’s got to face Steve. 

Billy surfaces slowly, giving Steve time to panic if he needs to. 

Steve does not panic. He’s staring at Billy like he’s never seen him before, eyes passing over Billy’s body in a kind of clinical detachment, as if even as he’s standing there, he’s thinking of all the possible ways he could take Billy apart if he needed.

Billy knows what he looks like. He inherited his scales from his mother, rich and vibrant hues of red and gold and blue, curling up his body in colorful streaks. The poisonous spines are reminiscent of lionfish, sprouting from his spine and curving back, away from him. The second set of eyelids that have closed over his eyes are black as ink, making his eyes look flat and soulless. 

And his teeth and claws… he would like to think that Steve hasn’t seen them yet. 

“Open your mouth,” Steve commands, his voice still hard.

Billy narrows his eyes. 

“What if I don’t want to?” he asks around a mouthful of teeth, annoyance lighting up his insides. 

Steve laughs, a touch hysterically. And then, slowly, the hysteria leaves his face, replaced with something tired.

“Please,” is all he says.

Billy closes his eyes. He opens his mouth.

For a moment, there is no sound between them, just the gurgle of the filtration system and the faint, distant sounds of the trees at Billy’s back. Insects. Wind. Owls.

When Billy opens his eyes, the bat is on the ground at Steve’s feet.

He’s drifted closer, almost to the edge of the pool now, and is stooping, peering at Billy closely. 

Billy watches him swallow. 

“Does anyone know?”

Billy almost doesn’t catch the words, so soft that the wind nearly carries them away. 

“My mom,” he says, tail lashing against the bottom of the pool. Steve watches the movement in something like horrified fascination. “No one else.”

Steve looks up. “Your dad-”

“No,” Billy says loudly. At Steve’s startled blink, he tries to reel himself back. Make the words softer, without teeth. “No. That would be- god, that would be a disaster.”

Steve is still watching him. 

“That’s why you were in the lake that night,” he says.

Billy nods, jerkily.

“And you’re not-” Steve swallows. “You’re not gonna eat me or anything, right?”

Billy chuckles bitterly. “Trust me, Steve. If I wanted to eat you I’ve had more than enough chances to do it.”

Steve edges closer, until his bare feet are touching the rim. He leans in over the water and Billy obligingly comes closer, doing a slow roll to show off the underside of his tail, the spines dotted thickly down his back, the silken frills at his waist.

“Can I touch?” Steve asks curiously.

Billy shrugs. “The spines are poisonous. But everything else… if you want.”

He doesn’t think Steve’s going to do it. He’s brave, but not- nobody would willingly get into the water with one of his kind, not just after finding out. But then again, Billy thinks, he hadn’t really thought anyone would make the jump to what he was either, and Steve already proved him wrong once tonight.

Steve stands and carefully steps out of his sweat pants, leaving him shivering in only his boxers. He hesitates for a moment, toes curling against the lip of the pool, and then with the look of someone ripping off a band-aid, jumps in.

When he surfaces, Billy is holding himself very still.

Steve has the look of someone who isn’t sure what they want to touch first, so Billy jerks his chin up, baring his throat to Steve. Steve watches his gills flutter for a moment, a hand outstretched between them. 

“It won’t hurt you?” he asks. “If I touch them?”

Billy swallows and says, in a gruff voice, “Just be careful.”

A moment later, cool fingertips brush up against the edge of his gills, stroking carefully. Steve’s touch is gentle, but it’s still unexpected, and he can’t stop his gills from flaring wide. Steve makes a strange quiet noise, something between curiosity and pleasure, and tentatively traces the edges, making Billy shudder. 

From there, Steve’s fingers map the rest of him. He takes care not to let his fingers near Billy’s spines, but the rest of him, Steve finds, brushing hands along scale and fin alike. He spends several long minutes touching the place where Billy’s belly gives way to hard scales, staring in fascination as Billy’s stomach shudders with every brush of his knuckles. 

“Oh,” Steve says. “You were born a fish. I get the joke.”

Billy snorts. 

He lets Steve continue petting at him for another few minutes, then gently draws Steve’s hands away from his body. He holds them in a loose grip between them and Steve stares at them too for a long minute, where Billy’s claws and webbed fingers wrap around his perfectly human wrists. 

“You aren’t scared of me?” Billy asks, cocking his head. 

Steve looks at him. Then slowly, he shakes his head. Shrugs a little, sheepish.

“I told you,” he says, drawing closer. There's a smile on his face. “I’ve met scarier monsters than you, Hargrove.”

Billy swallows. "You'll have to tell me about that sometime."

Steve hums a little, deep in his throat, and leans in, just enough to set his brow against Billy's.

"Maybe later," he whispers.

**Author's Note:**

> [My tumblr.](https://callunavulgari.tumblr.com/)


End file.
